a. Field of the Invention
This invention relates to soil sample extraction tools, and in particular, to soil sample extraction tools which allow easy access to the soil sample after it is extracted from the soil.
b. Problems in the Art
Many soil sampling devices have been developed and are in use. Their uses are varied and their objectives differ for those uses. For example, some soil sample devices are used simply to extract a quantity of soil from a given location or depth. Others are aimed at obtaining and preserving a representative sample of layers of soil so it can be studied in an undisturbed state.
Significant problems exist in obtaining undisturbed core samples. Most tools involve forcibly inserting a tool into the soil to a desired depth or soil sample position. A container in the soil sample tool then captures the desired soil sample core, and then the tool allows extraction of that sample from the ground.
Problems exist in, first, designing the tool so that the targeted soil sample is not altered by the means used by the tool to reach the soil sample. Some tools have cutting or boring heads which disturb or otherwise alter the targeted soil sample. Secondly, many tools have the problem of compacting or squeezing the soil as the sample is being obtained. Third, many present tools allow, or do not prevent, leaching or contamination of the sample by surrounding soil, either as the tool is being inserted, as the sample is being taken, or as the tool is being extracted. An additional problem is that many tools are configured so as to make it difficult to remove the soil sample from the tool for study while keeping the sample intact.
A common soil sample tool comprises a tubular container having a cutting tip. The container is inserted into the ground and the soil sample fills up the container. The tool is then removed from the soil. Because access to the soil sample chamber in the tools is many times through the cutting opening only, it is difficult to remove the soil sample which is basically compactionally held therein.
Other tools have therefore utilized a tubular container having an open, uncovered access along its side. The cutting tip still causes a cylindrical core sample to be taken into the container, but once extracted from the soil, the sample can basically be lifted out of the container, or analyzed as it is held therein. A significant difficulty is that surrounding soil can invade into the sample chamber through the opening, and that exposed part of the sample can be eroded, leached or scraped away, diminishing the value of the sample or the ability to accurately analyze it.
Some attempts have been made to retain the benefit of having a completely closed container, but still allowing access through the side of the container to the sample. Many of these attempts have been unreliable, in that they allow leaching or alteration of the sample during its taking, or are difficult to use. Others are complex to the point where they are uneconomical or inefficient for use as soil sampling devices.
These problems are particularly evident in situations where the sampling tool must be rotated or pivoted as it moves through the soil. Examples of such tools are called soil sampling augers. As is evident, rotation through the soil requires sampling tools which have minimal resistance to rotation, and which do not have outward protrusions so that the tool can easily cut through the soil. Also, there must be minimal resistance or protrusion of any part of the tool in the sample receiving chamber so that the soil sample can smoothly and easily pass into the chamber.
Many present attempts at developing soil sampling tools which allow easy access to the soil sample after extraction are insufficient or deficient in these respects. It is therefore a principal object of the present invention to provide a soil sample extraction tool which solves or improves over the problems and deficiencies in the art.
Another object of the present invention is to provide a tool as above described which allows the obtaining and extraction of accurate soil samples, and easy access to those samples.
A further object of the present invention is to provide a tool as above described, which causes minimal disruption of the sample.
A further object of the present invention is to provide a tool as above described which can obtain a reliable sample from a number of different soil types and conditions.
Another object of the present invention is to provide a tool as above described which is non-complex, easy to use, and easy to maintain.
A further object of the present invention is to provide a tool as above described which allows easy access to an extracted soil sample, but does not cause unnecessary disruption of the soil or the soil sample by a structure.
Another object of the present invention is to provide a tool as above described which is efficient, durable and economical.
These and other objects, features, and advantages of the invention will become more apparent with reference to the accompanying specification and claims.